You can simply try this eSoftTools Best OST to PST Converter Software to restore all lost database items from corrupt OST files like emails, contacts, chats, tasks, notes, journals, appointments to save them to a new Outlook PST file and many other file formats. This tool offers the user to convert OST to PST Free, EML, EMLX, MSG, HTML, vCard, CSV, MBOX, and Office 365. A free Demo version of this software is also available of this which can instantly export the selective 50 items from each folder of OST file to Outlook PST or another format without any charges.
For More Info:- Convert OST to PST Free